1. Field of the Invention
This invention relates to a new and improved liquid level adjusting and filtering device which is automatically operable to adjust to a predetermined and precisely repeatable location the level of, and to filter, a liquid in a test tube or like container into which the device is inserted; and which is, in combination with said container, particulalrly adapted for use in automated sample liquid analysis systems to present each of a plurality of sample liquids in turn to the analysis system aspirating probe means at precisely the same level.
2. Description of the prior art
The most relevant prior art known to applicants is that embodied by the sample liquid filtering device as marketed under the Trademark "SERACLEAR" by applicants' assignee, Technicon Instruments Corporation, of Tarrytown, N.Y. Although, as illustrated and described in detail in this specification, this prior art filtering device does effectively function to filter a sample liquid in a test tube or like container into which the device is inserted for presentation to the aspirating probe means of an automated sample liquid analysis system, the same does not operate to automatically adjust the level of the thusly presented sample liquid to a predetermined and precisely repeatable location relative to those aspirating probe means.
Also relevant to this invention is the Serum Separator And Fibrin Filter as disclosed in U.S. Pat. No. 3,929,646 issued Dec. 30, 1975 to Stanford L. Adler and assigned to the assignee hereof. Although this separator does effectively function attendant sample liquid centrifugation with the separator inserted in the sample liquid container to separate and filter the blood serum constituent of a blood sample for presentation to the aspirating probe means of automated sample liquid analysis system, the same is again totally ineffective to automatically adjust the level of the thusly presented blood serum sample to a predetermined and precisley repeatable location relative to those aspirating probe means.
In addition, although automated sample liquid analysis systems are believed to now exist which include means to automatically adjust the level of the sample liquid containers to present the sample liquids as contained therein to the system aspirating probe means at the same level, these systems clearly do not anticipate the subject matter of this invention.